From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
On experiments proving a Goshawk dynamo fault can be caused by a sticking negative brush.
| Identifier | WestWitteringFiles\K\October1923\ Scan51 | |
| Date | 12th October 1923 | |
| M ORIGINAL To R & R.{Sir Henry Royce} from EFC. c. CJ. & PH. c. EY. EP.{G. Eric Platford - Chief Quality Engineer} DA.{Bernard Day - Chassis Design} EFC4/T12.10.23. X.4383 - GOSHAWK DYNAMO. ------------------------ We have now completed experiments proving the suggestion contained in our EFC4/T27.9.23. that the dynamo can be, due to the sticking negative brush (the brush bedding being otherwise good) in a condition where it will fling the commutator solder, even though working normally to all external appearances, s.g. as regards the output indicated on the ammeter. These experiments are repeated in my assistant's reports AB.88 and AB.89 , copies herewith, from which it will be seen that the field volts and therefore the E.M.F. of the machine may be increased abnormally even though the main ampere output and main volts are normal. The point we wish to emphasize is that this is an instance of which the dynamo can be in the wrong condition without the ammeter giving evidence of it. EFC. | ||